Toshiba GR200 Series Instruction Manual page 374

Operation characteristic
2.27.1
Two elements are provided to detect an out-of-step condition. Figure 2.27-1 shows the operation
principle of the OSTV function. Reference voltage (V A ) is acquired in IED A at terminal A; and
a corresponding voltage (V B ) is acquired in IED B at terminal B. Using the telecommunication
voltage data at both terminals are provided to the respective opposite terminals. Electrical
center is located at which the respective impedances for respective terminals are equal.
Z
A
Terminal A
Left impedance
(Z
Figure 2.27-1 Typical impedance and electrical center
Note: The data is transferred by the function of 'Communication application'. For more
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information, see Chapter
Figure 2.27-2 is the characteristic of the OSTV-1 element. Phasor V B will exist in the
second quadrant (α-zone) or the third quadrant (β-zone) if the out-of-step state is appeared.
This is because a reference voltage is obtained at terminal A.
Figure 2.27-2 Voltage phase comparison between terminal A and terminal B (OSTV-1)
Electrical center
V
A
Data of V
IED A
Data of V
Telecommunication
+Z +Z )/2
A L B
Relay application: Communication application
-zone
V B
-zone
- 351 -
Z
L
V
B
B
IED B
A
Right impedance
(Z +Z +Z )/2
A L B
1V
V A
6F2S1914 (0.49)
Z
B
Terminal B
.
GRL200 (Soft 033 & 037)
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